Sales of glass-ceramic hotplates have been growing continuously for several years.
The glass-ceramic hotplates can be electric hotplates. The plates are flat plates that are initially made from a glass-ceramic precursor and then ceramicized.
The hotplates can also be halogen or induction hotplates.
However, this kind of glass-ceramic hotplate is also produced for gas cookers or combined hobs, in particular combined gas/electric hobs. Openings must be provided in this type of plate for gas burners to pass through. The diameter of the openings is made sufficiently large, compared to the diameters of the burners, for the burners to be fitted without forcing them, so that there is therefore no risk of breaking the plate. The diameter is generally from 40 millimeters (mm) to 95 mm.
Smaller openings can also be provided in all types of plate, in particular for fitting control knobs.
Glass-ceramic hotplates have been increasingly successful over the past several years, in particular because of their attractive appearance and because they are easy to clean.
Their appearance can be further improved by applying a decorative coating, generally of enamel.
Nevertheless, all existing glass-ceramic plates still have some drawbacks in use. In particular, they scratch easily because of friction with saucepans and cleaning scourers. They are also easily discolored because of friction with metals.
Another drawback is that food still sticks to the plates too easily, which leads the user to clean them with scourers, causing further scratches.
The invention aims to alleviate those drawbacks by proposing a glass-ceramic plate that has an improved hardness and scratch-resistance, which has a reduced coefficient of friction to reduce discoloration caused by metals, and has a reduced adhesion of food to these surfaces, without compromising their efficiency and attractive appearance.